net: ipa: only reset hashed tables when supported

Last year, the code that manages GSI channel transactions switched
from using spinlock-protected linked lists to using indexes into the
ring buffer

net: ipa: only reset hashed tables when supported

Last year, the code that manages GSI channel transactions switched
from using spinlock-protected linked lists to using indexes into the
ring buffer used for a channel. Recently, Google reported seeing
transaction reference count underflows occasionally during shutdown.

Doug Anderson found a way to reproduce the issue reliably, and
bisected the issue to the commit that eliminated the linked lists
and the lock. The root cause was ultimately determined to be
related to unused transactions being committed as part of the modem
shutdown cleanup activity. Unused transactions are not normally
expected (except in error cases).

The modem uses some ranges of IPA-resident memory, and whenever it
shuts down we zero those ranges. In ipa_filter_reset_table() a
transaction is allocated to zero modem filter table entries. If
hashing is not supported, hashed table memory should not be zeroed.
But currently nothing prevents that, and the result is an unused
transaction. Something similar occurs when we zero routing table
entries for the modem.

By preventing any attempt to clear hashed tables when hashing is not
supported, the reference count underflow is avoided in this case.

Note that there likely remains an issue with properly freeing unused
transactions (if they occur due to errors). This patch addresses
only the underflows that Google originally reported.

Cc: <stable@vger.kernel.org> # 6.1.x
Fixes: d338ae28d8a8 ("net: ipa: kill all other transaction lists")
Tested-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Alex Elder <elder@linaro.org>
Link: https://lore.kernel.org/r/20230724224055.1688854-1-elder@linaro.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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net: ipa: generalize register field functions

Rename functions related to register fields so they don't appear to
be IPA-specific, and move their definitions into "reg.h":
ipa_reg_fmask() -> reg

net: ipa: generalize register field functions

Rename functions related to register fields so they don't appear to
be IPA-specific, and move their definitions into "reg.h":
ipa_reg_fmask() -> reg_fmask()
ipa_reg_bit() -> reg_bit()
ipa_reg_field_max() -> reg_field_max()
ipa_reg_encode() -> reg_encode()
ipa_reg_decode() -> reg_decode()

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

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net: ipa: generalize register offset functions

Rename ipa_reg_offset() to be reg_offset() and move its definition
to "reg.h". Rename ipa_reg_n_offset() to be reg_n_offset() also.

Signed-off-by: Al

net: ipa: generalize register offset functions

Rename ipa_reg_offset() to be reg_offset() and move its definition
to "reg.h". Rename ipa_reg_n_offset() to be reg_n_offset() also.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

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net: ipa: start generalizing "ipa_reg"

IPA register definitions have evolved with each new version. The
changes required to support more than 32 endpoints in IPA v5.0 made
it best to define a unifi

net: ipa: start generalizing "ipa_reg"

IPA register definitions have evolved with each new version. The
changes required to support more than 32 endpoints in IPA v5.0 made
it best to define a unified mechanism for defining registers and
their fields.

GSI register definitions, meanwhile, have remained fairly stable.
And even as the total number of IPA endpoints goes beyond 32, the
number of GSI channels on a given EE that underly endpoints still
remains 32 or less.

Despite that, GSI v3.0 (which is used with IPA v5.0) extends the
number of channels (and events) it supports to be about 256, and as
a result, many GSI register definitions must change significantly.
To address this, we'll use the same "ipa_reg" mechanism to define
the GSI registers.

As a first step in generalizing the "ipa_reg" to also support GSI
registers, isolate the definitions of the "ipa_reg" and "ipa_regs"
structure types (and some supporting macros) into a new header file,
and remove the "ipa_" and "IPA_" from symbol names.

Separate the IPA register ID validity checking from the generic
check that a register ID is in range. Aside from that, this is
intended to have no functional effect on the code.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

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net: ipa: support zeroing new cache tables

IPA v5.0+ separates the configuration of entries in the cached
(previously "hashed") routing and filtering tables into distinct
registers. Previously a si

net: ipa: support zeroing new cache tables

IPA v5.0+ separates the configuration of entries in the cached
(previously "hashed") routing and filtering tables into distinct
registers. Previously a single "filter and router" register updated
entries in both tables at once; now the routing and filter table
caches have separate registers that define their content.

This patch updates the code that zeroes entries in the cached filter
and router tables to support IPA versions including v5.0+.

Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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net: ipa: update table cache flushing

Update the code that causes filter and router table caches to be
flushed so that it supports IPA versions 5.0+. It adds a comment in
ipa_hardware_config_hashin

net: ipa: update table cache flushing

Update the code that causes filter and router table caches to be
flushed so that it supports IPA versions 5.0+. It adds a comment in
ipa_hardware_config_hashing() that explains that cacheing does not
need to be enabled, just as before, because it's enabled by default.
(For the record, the FILT_ROUT_CACHE_CFG register would have been
used if we wanted to explicitly enable these.)

Signed-off-by: Alex Elder <elder@linaro.org>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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net: ipa: avoid a null pointer dereference

Dan Carpenter reported that Smatch found an instance where a pointer
which had previously been assumed could be null (as indicated by a
null check) was lat

net: ipa: avoid a null pointer dereference

Dan Carpenter reported that Smatch found an instance where a pointer
which had previously been assumed could be null (as indicated by a
null check) was later dereferenced without a similar check.

In practice this doesn't lead to a problem because currently the
pointers used are all non-null. Nevertheless this patch addresses
the reported problem.

In addition, I spotted another bug that arose in the same commit.
When the command to initialize a routing table memory region was
added, the number of entries computed for the non-hashed table
was wrong (it ended up being a Boolean rather than the count
intended). This bug is fixed here as well.

Reported-by: Dan Carpenter <error27@gmail.com>
Link: https://lore.kernel.org/kernel-janitors/Y3OOP9dXK6oEydkf@kili
Tested-by: Caleb Connolly <caleb.connolly@linaro.com>
Fixes: 5cb76899fb47 ("net: ipa: reduce arguments to ipa_table_init_add()")
Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

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net: ipa: support more filtering endpoints

Prior to IPA v5.0, there could be no more than 32 endpoints.

A filter table begins with a bitmap indicating which endpoints have
a filter defined. That b

net: ipa: support more filtering endpoints

Prior to IPA v5.0, there could be no more than 32 endpoints.

A filter table begins with a bitmap indicating which endpoints have
a filter defined. That bitmap is currently assumed to fit in a
32-bit value.

Starting with IPA v5.0, more than 32 endpoints are supported, so
it's conceivable that a TX endpoint has an ID that exceeds 32.
Increase the size of the field representing endpoints that support
filtering to 64 bits. Rename the bitmap field "filtered".

Unlike other similar fields, we do not use an (arbitrarily long)
Linux bitmap for this purpose. The reason is that if a filter table
ever *did* need to support more than 64 TX endpoints, its format
would change in ways we can't anticipate.

Have ipa_endpoint_init() return a negative errno rather than a mask
that indicates which endpoints support filtering, and have that
function assign the "filtered" field directly.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

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net: ipa: use ipa_table_mem() in ipa_table_reset_add()

Similar to the previous commit, pass flags rather than a memory
region ID to ipa_table_reset_add(), and there use ipa_table_mem() to
look up th

net: ipa: use ipa_table_mem() in ipa_table_reset_add()

Similar to the previous commit, pass flags rather than a memory
region ID to ipa_table_reset_add(), and there use ipa_table_mem() to
look up the memory region affected based on those flags.

Currently all eight of these table memory regions are assumed to
exist, because they all have canaries within them. Stop assuming
that will always be the case, and in ipa_table_reset_add() allow
these memory regions to be non-existent.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

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net: ipa: reduce arguments to ipa_table_init_add()

Recently ipa_table_mem() was added as a way to look up one of 8
possible memory regions by indicating whether it was a filter or
route table, hashe

net: ipa: reduce arguments to ipa_table_init_add()

Recently ipa_table_mem() was added as a way to look up one of 8
possible memory regions by indicating whether it was a filter or
route table, hashed or not, and IPv6 or not.

We can simplify the interface to ipa_table_init_add() by passing two
flags to it instead of the opcode and both hashed and non-hashed
memory region IDs. The "filter" and "ipv6" flags are sufficient to
determine the opcode to use, and with ipa_table_mem() can look up
the correct memory region as well.

It's possible to not have hashed tables, but we already verify the
number of entries in a filter or routing table is nonzero. Stop
assuming a hashed table entry exists in ipa_table_init_add().

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

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net: ipa: no more global filtering starting with IPA v5.0

IPA v5.0 eliminates the global filter table entry. As a result,
there is no need to shift the filtered endpoint bitmap when it is
written t

net: ipa: no more global filtering starting with IPA v5.0

IPA v5.0 eliminates the global filter table entry. As a result,
there is no need to shift the filtered endpoint bitmap when it is
written to IPA local memory.

Update comments to explain this. Also delete a redundant block of
comments above the function.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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net: ipa: determine filter table size from memory region

Currently we assume that any filter table contains a fixed number
of entries. Like routing tables, the number of entries in a filter
table i

net: ipa: determine filter table size from memory region

Currently we assume that any filter table contains a fixed number
of entries. Like routing tables, the number of entries in a filter
table is limited only by the size of the IPA-local memory region
used to hold the table.

Stop assuming that a filter table has exactly 14 entries. Instead,
determine the number of entries in a routing table by dividing its
memory region size by the size of an entry. (Note that the first
"entry" in a filter table contains an endpoint bitmap.)

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

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net: ipa: don't assume 8 modem routing table entries

Currently all platforms are assumed allot 8 routing table entries
for use by the modem. Instead, add a new configuration data entry
that defines

net: ipa: don't assume 8 modem routing table entries

Currently all platforms are assumed allot 8 routing table entries
for use by the modem. Instead, add a new configuration data entry
that defines the number of modem routing table entries, and record
that in the IPA structure.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

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net: ipa: determine route table size from memory region

Currently we assume that any routing table contains a fixed number
of entries. The number of entries in a routing table can actually
vary, de

net: ipa: determine route table size from memory region

Currently we assume that any routing table contains a fixed number
of entries. The number of entries in a routing table can actually
vary, depending only on the size of the IPA-local memory region used
to hold the table.

Stop assuming that a routing table has exactly 15 entries. Instead,
determine the number of entries in a routing table by dividing its
memory region size by the size of an entry.

The number of entries is computed early, when ipa_table_mem_valid()
is called by ipa_table_init().

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

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net: ipa: record the route table size in the IPA structure

The non-hashed routing tables for IPv4 and IPv6 will be the same
size. And if supported, the hashed routing tables will be the same
size a

net: ipa: record the route table size in the IPA structure

The non-hashed routing tables for IPv4 and IPv6 will be the same
size. And if supported, the hashed routing tables will be the same
size as the non-hashed tables.

Record the size (number of entries) of all routing tables in the IPA
structure. For now, initialize this field using IPA_ROUTE_TABLE_MAX,
and just do so when the first route table is validated.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

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net: ipa: check table memory regions earlier

Verify that the sizes of the routing and filter table memory regions
are valid as part of memory initialization, rather than waiting for
table initializa

net: ipa: check table memory regions earlier

Verify that the sizes of the routing and filter table memory regions
are valid as part of memory initialization, rather than waiting for
table initialization. The main reason to do this is that upcoming
patches use these memory region sizes to determine the number of
entries in these tables, and we'll want to know these sizes are good
sooner.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

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net: ipa: kill ipa_table_valid()

What ipa_table_valid() (and ipa_table_valid_one(), which it calls)
does is ensure that the memory regions that hold routing and filter
tables have reasonable size.

net: ipa: kill ipa_table_valid()

What ipa_table_valid() (and ipa_table_valid_one(), which it calls)
does is ensure that the memory regions that hold routing and filter
tables have reasonable size. Specifically, it checks that the size
of a region is sufficient (or rather, exactly the right size) to
hold the maximum number of entries supported by the driver. (There
is an additional check that's erroneous, but in practice it is never
reached.)

Recently ipa_table_mem_valid() was added, which is called by
ipa_table_init(). That function verifies that all table memory
regions are of sufficient size, and requires hashed tables to have
zero size if hashing is not supported. It only ensures the filter
table is large enough to hold the number of endpoints that support
filtering, but that is adequate.

Therefore everything that ipa_table_valid() does is redundant, so
get rid of it.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

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net: ipa: verify table sizes fit in commands early

We currently verify the table size and offset fit in the immediate
command fields that must encode them in ipa_table_valid_one(). We
can now make

net: ipa: verify table sizes fit in commands early

We currently verify the table size and offset fit in the immediate
command fields that must encode them in ipa_table_valid_one(). We
can now make this check earlier, in ipa_table_mem_valid().

The non-hashed IPv4 filter and route tables will always exist, and
their sizes will match the IPv6 tables, as well as the hashed tables
(if supported). So it's sufficient to verify the offset and size of
the IPv4 non-hashed tables fit into these fields.

Rename the function ipa_cmd_table_init_valid(), to reinforce that
it is the TABLE_INIT immediate command fields we're checking.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

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net: ipa: validate IPA table memory earlier

Add checks in ipa_table_init() to ensure the memory regions defined
for IPA filter and routing tables are valid.

For routing tables, the checks ensure:

net: ipa: validate IPA table memory earlier

Add checks in ipa_table_init() to ensure the memory regions defined
for IPA filter and routing tables are valid.

For routing tables, the checks ensure:
- The non-hashed IPv4 and IPv6 routing tables are defined
- The non-hashed IPv4 and IPv6 routing tables are the same size
- The number entries in the non-hashed IPv4 routing table is enough
to hold the number entries available to the modem, plus at least
one usable by the AP.

For filter tables, the checks ensure:
- The non-hashed IPv4 and IPv6 filter tables are defined
- The non-hashed IPv4 and IPv6 filter tables are the same size
- The number entries in the non-hashed IPv4 filter table is enough
to hold the endpoint bitmap, plus an entry for each defined
endpoint that supports filtering.

In addition, for both routing and filter tables:
- If hashing isn't supported (IPA v4.2), hashed tables are zero size
- If hashing *is* supported, all hashed tables are the same size as
their non-hashed counterparts.

When validating the size of routing tables, require the AP to have
at least one entry (in addition to those used by the modem).

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

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net: ipa: kill two constant symbols

The entries in each IPA routing table are divided between the modem
and the AP. The modem always gets some number of entries located at
the base of the table; th

net: ipa: kill two constant symbols

The entries in each IPA routing table are divided between the modem
and the AP. The modem always gets some number of entries located at
the base of the table; the AP gets all those that follow.

There's no reason to think the modem will use anything different
from the first entries in a routing table, so:
- Get rid of IPA_ROUTE_MODEM_MIN (just assume it's 0)
- Get rid of IPA_ROUTE_AP_MIN (just assume it's IPA_ROUTE_MODEM_COUNT)
And finally:
- Open-code IPA_ROUTE_AP_COUNT and remove its definition

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

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net: ipa: update copyrights

Some source files state copyright dates that are earlier than the
last modification of the file. Change the copyright year to 2022 in
all such cases.

Signed-off-by: Ale

net: ipa: update copyrights

Some source files state copyright dates that are earlier than the
last modification of the file. Change the copyright year to 2022 in
all such cases.

Signed-off-by: Alex Elder <elder@linaro.org>
Link: https://lore.kernel.org/r/20220930224549.3503434-1-elder@linaro.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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net: ipa: define remaining IPA register fields

Define the fields for the ENDP_INIT_DEAGGR, ENDP_INIT_RSRC_GRP,
ENDP_INIT_SEQ, ENDP_STATUS, and ENDP_FILTER_ROUTER_HSH_CFG, and
IPA_IRQ_UC IPA register

net: ipa: define remaining IPA register fields

Define the fields for the ENDP_INIT_DEAGGR, ENDP_INIT_RSRC_GRP,
ENDP_INIT_SEQ, ENDP_STATUS, and ENDP_FILTER_ROUTER_HSH_CFG, and
IPA_IRQ_UC IPA registers for all supported IPA versions.

Create enumerated types to identify fields for these IPA registers.
Use IPA_REG_FIELDS() and IPA_REG_STRIDE_FIELDS() to specify the
field mask values defined for these registers, for each supported
version of IPA.

Use ipa_reg_encode() and ipa_reg_bit() to build up the values to be
written to these registers, remove an inline function and all the
*_FMASK symbols that are now no longer used.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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net: ipa: define some more IPA register fields

Define the fields for the SHARED_MEM_SIZE, QSB_MAX_WRITES,
QSB_MAX_READS, FILT_ROUT_HASH_EN, and FILT_ROUT_HASH_FLUSH IPA
registers for all supported I

net: ipa: define some more IPA register fields

Define the fields for the SHARED_MEM_SIZE, QSB_MAX_WRITES,
QSB_MAX_READS, FILT_ROUT_HASH_EN, and FILT_ROUT_HASH_FLUSH IPA
registers for all supported IPA versions.

Create enumerated types to identify fields for these registers. Use
IPA_REG_FIELDS() to specify the field mask values defined for these
registers, for each supported version of IPA.

Use ipa_reg_bit() and ipa_reg_encode() to build up the values to be
written to these registers rather than using the *_FMASK
preprocessor symbols.

Remove the definition of the now unused *_FMASK symbols.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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net: ipa: introduce ipa_reg()

Create a new function that returns a register descriptor given its
ID. Change ipa_reg_offset() and ipa_reg_n_offset() so they take a
register descriptor argument rathe

net: ipa: introduce ipa_reg()

Create a new function that returns a register descriptor given its
ID. Change ipa_reg_offset() and ipa_reg_n_offset() so they take a
register descriptor argument rather than an IPA pointer and register
ID. Have them accept null pointers (and return an invalid 0 offset),
to avoid the need for excessive error checking. (A warning is issued
whenever ipa_reg() returns 0).

Call ipa_reg() or ipa_reg_n() to look up information about the
register before calls to ipa_reg_offset() and ipa_reg_n_offset().
Delay looking up offsets until they're needed to read or write
registers.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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net: ipa: use IPA register IDs to determine offsets

Expose two inline functions that return the offset for a register
whose ID is provided; one of them takes an additional argument
that's used for r

net: ipa: use IPA register IDs to determine offsets

Expose two inline functions that return the offset for a register
whose ID is provided; one of them takes an additional argument
that's used for registers that are parameterized. These both use
a common helper function __ipa_reg_offset(), which just uses the
offset symbols already defined.

Replace all references to the offset macros defined for IPA
registers with calls to ipa_reg_offset() or ipa_reg_n_offset().

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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